An unnamed first-person narrator shelters in a diner of a truck stop with a small group of bewildered people. They cower behind the banquettes and stare uncertainly at the few trucks clustered in the parking lot. When Snodgrass, a “potbell[ied]” salesman, attempts to flee, a truck springs to life and runs directly into him. The truck thrusts Snodgrass into a ditch, where he takes hours to die. The narrator, still in the diner with the others, relates a tale familiar to them: Hours before, he was travelling on a nearby highway when a semi-trailer started knocking other cars off the road, killing drivers and destroying cars. The others have had similar experiences. None of them can explain why, but large trucks and busses have come to life and begun killing all humans.

Five survivors remain in the diner: the narrator, an elderly short-order cook (counterman), a teen named Jerry and his girlfriend, and a trucker. They plan to wait out the malevolent trucks in the diner. The counterman assures them that the diner has enough food to feed them for a month. However, when the power goes out, the counterman relays that the refrigerated food will spoil in three days. He also communicates that they will need to collect the drinkable water from the bathrooms if they are to subsist.